Task Force (TF)...it the trade name Chevrolet gave to it's trucks made from 1955 (second) thru 59.
These motor mounts bolt to two bolt holes on either side of the timing gear cover (at the engine) and the frame brackets bolt into the three factory holes on the cross member.
What you are discribing are the true "side motor mounts" which started in 1958, but the trucks and Corvette's still used the front mounts for many more years. The holes needed were drilled and tapped in the blocks up until about 1970 (don't quote me on the date).
Mike B
